1. Field of the Invention
The present invention relates to a scissor coupler for attaching a trailer to a trailer hitch ball, and more particularly, the present invention relates to a self-locking scissor coupler for attaching a trailer to a trailer hitch ball.
2. Description of the Prior Art
Numerous innovations for trailer couplers have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
A FIRST EXAMPLE, U.S. Pat. No. 4,568,098, Issued on Feb. 4, 1986, to Landry, Jr. teaches a trailer hitch adapted for attachment to a lunette coupler or a ball coupler comprises a pintle hook and a ball mounted on the hook and adapted to receive a ball coupler, and a closure pivotally mounted on the hook and pivotable between a closed position in engagement with the ball and an open position spaced from the ball. The aperture defined by the closure and the hook includes a lower circular open portion, the center point of the lower circular portion lying on a first horizontal plane substantially bisecting the pattern of attachment of the hitch, the first horizontal plane lying below a second horizontal plane projected tangent to the under surface of the ball, the rearmost point within the aperture defined by the pintle hook and the closure in closed position to receive and hold the lunette, lying the further rearward from the vertical plane of the attachment plate, lies within the lower circular portion of the aperture in a horizontal plane passing through the center of the attachment pattern, whereby during towing, the load of the trailer attached by the lunette is evenly distributed over the pattern of attachment. In one further aspect, the hitch includes a second configuration, e.g. a second ball, which may be selectively positioned for towing attachment.
A SECOND EXAMPLE, U.S. Pat. No. 5,205,666, Issued on Apr. 27, 1993, to Hollis teaches an improved trailer coupler is provided for a trailer having a forwardly extending tongue, which consists of a housing fixed on and extending forwardly from the tongue. A pair of opposed jaws are pivoted on vertical axes on the housing. Each jaw has an inner side formed with a spherical concavity for embracing a hitch ball and a surface for forcing said improved trailer coupler to align with a said hitch ball. A jaw locking bail has a bight portion with a finger tab to facilitate operation of the bail and a pair of side portions, each with an ear extension. The side portions are horizontally pivoted on the housing at the ear extension at opposite sides of the housing. The ball is swingable forwardly and downwardly from an elevated retracted position to a horizontal jaw-locking position, wherein the side portions completely engage the outer sides of the jaws and the bight portion completely engages the forward ends of the jaws in the closed positions of the jaws. A closure compression spring is located inwardly at one horizontally pivoted ear extension for biasing the bail towards the jaw-locking position.
A THIRD EXAMPLE, U.S. Pat. No. 5,482,309, Issued on Jan. 9, 1996, to Hollis teaches a scissor coupler, for attaching to a trailer hitch ball having a widest point and a neck, comprising a top plate, a bottom plate, a hinge bolt, and a main spring connected between the top plate and bottom plate. The hinge bolt attaches the top plate and bottom plate so that they can pivot relative to one another from a closed position to an open position. The top plate and bottom plate have top plate and bottom plate bores that have a slightly larger diameter than the widest point of the trailer hitch ball, and are concentric when the top plate and bottom plate are in the open position. The top plate and bottom plate bores are not concentric when the scissor coupler is in the closed position. When the top plate and bottom plate are in the closed position, an elliptical hole is formed therebetween that is narrower than the widest point but wider than the neck of the trailer hitch ball. The main spring biases the scissor coupler to the closed position.
A FOURTH EXAMPLE, U.S. Pat. No. 5,997,025, Issued on Dec. 7, 1999, to Wisecarver teaches a trailer hitch including a pair of clamping jaws and a retractable jaw locking member in the form of a wedge block that is spring biased to move between the jaws in order to lock the jaws in a closed position about a hitch ball. A latch mechanism secures the wedge block in its retracted position away from the jaws. A plunger dog is pivoted by a handle mechanism to reposition wedge block and a safety pin mechanism is provided to secure the plunger dog in position and thereby secure wedge block in position.
A FIFTH EXAMPLE, U.S. Pat. No. 6,224,084 B1, Issued on May 1, 2001, to Ray et al. teaches a trailer coupler is described in which a pair of elongated hitch capturing members, each having a hitch socket part at a forward end are mounted to a base member for selective movement forward and rearwardly between a forwardly extended and open hitch receiving position wherein the hitch socket parts are separated and a rearwardly retracted and closed hitch capturing position wherein the hitch socket parts are closed together. A hitch positioner member is movably mounted to the base member and including a hitch abutment surface positioned between the hitch capturing members in the forwardly extended and open hitch receiving position. The hitch positioner member is connected to at least one of the hitch capturing members to move the hitch capturing member rearwardly in response to engagement by a rearwardly moving hitch. Interacting cam surfaces on at least one of the hitch capturing members and base member are responsive to rearward motion of the hitch capturing members to move the hitch capturing members to the closed hitch capturing position responsive to rearward movement of the hitch capturing members.
A SIXTH EXAMPLE, U.S. Pat. No. 6,234,509 B1, Issued on May 22, 2001, to Lara teaches a device and method for coupling a trailer which has a trailer tongue mount attached to the trailer and a coupler attached to the trailer tongue mount. The coupler has an outer tube assembly, an inner tube assembly slidably received by the outer tube assembly, and a return spring having a first end attached to the outer tube assembly, and a second end attached to the inner tube assembly for drawing the inner tube assembly upwardly toward the first end of the return spring. The inner tube assembly may include an inner tubular member which has a plurality of height adjusting holes, a top end and a bottom end. The inner tube assembly may also include a female coupling member attached to the bottom end of the tubular member. A locking handle assembly may be attached to the inner tube assembly to prevent the coupler from disengaging from the towing vehicle. The outer tube assembly may include an outer tubular member, a reinforcing band attached to the outer tubular member, an adjusting nut attached to the reinforcing band, and an adjusting bolt in communication with the nut to provide a friction force on the inner tube assembly. A plunger pin may engage one of the adjusting holes in the inner tube assembly. A snapper pin may be used to indicate that the plunger pin is properly closed.
A SEVENTH EXAMPLE, U.S. Pat. No. 6,485,046 B1, Issued on Nov. 26, 2002, to Hsueh et al. teaches a trailer hitch assembly for connecting a towing vehicle to a towed trailer having symmetrical anti-sway features. The assembly includes a hitch ball rigidly affixed to a hitch beam extending transversely from the rear of the towing vehicle. A pair of spring-biased telescopic compressible and extendable control rods are connected to each end of the hitch beam and at their other end to a control beam. A hitch bar is connected to the hitch ball on the towing vehicle and pivotally connected to the forward end of a trailer coupler that intersects and is pivotally connected to the central portion of the control beam by a pivot member. The pivot member is integral with the control beam and includes a control arm having a roller engaged with a downwardly opening slotted rearward end of the hitch bar. The trailer coupler includes a trailer hitch ball to which a trailer coupler socket is connected, with the trailer coupler socket being rigidly affixed to the tongue or frame of the towed vehicle.
AN EIGHTH EXAMPLE, U.S. patent Office Document No. 2005/0039498 A1, Published on Feb. 24, 2005, to Budge teaches a trailer coupler locking device having a shackle which has a top joined to two substantially straight legs with a curved section that is preferably a generally convex curve. The base contains a cylinder lock symmetrically located between two apertures for accommodating the substantially straight legs of the shackle. A plug member is located on top of the base; preferably the plug member is a stepped ball. Associated with the cylinder lock are two bolts, one of which has an end that enters the first aperture for the straight legs and another of which has an end that enters the second aperture for the straight legs. A blocking member works with the cylinder lock to control the movement of the straight legs and preferably has three positions for doing so which are associated with the positions of the preferred cylinder lock, which is a three-position lock.
It is apparent that numerous innovations for trailer couplers have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.